In 2007, the United States implemented federal laws requiring most passenger vehicles to include a tire pressure monitoring system (TPMS) to monitor and alert drivers of low tire pressure which degrades vehicle efficiency and performance. Continued use of a tire with low tire pressure can cause premature wear of the tire and in the worst case, catastrophic tire failure.
One TPMS system is so-called direct TPMS. In direct TPMS, a tire sensor is installed in the wheels of each pneumatic vehicle tire, often on the valve stem. These sensors are capable of monitoring several conditions of the tire including: tire air pressure, tire temperature, wheel rotation speed and other conditions. The sensors themselves include a specific sensor identification code (ID) and are capable of receiving external electronic signals from an electronic control unit or module (ECU) in the vehicle, and in response, sending electronic signals wirelessly from inside the wheel to the vehicle ECU, which typically is connected to alert indications in the instrument panel in the interior of the passenger compartment. If a wheel sensor senses a tire pressure or other condition in a tire that is above or below a predetermined level, the sensor transmits a signal that is received by the ECU, and the ECU triggers an audio/visual indication to alert the driver to the condition. The sensors are similarly capable of receiving external electronic signals from an external TPMS monitoring tool and sending the electronic signals wirelessly from inside the wheel to the external tool.
Typical tire sensors used with TPMS systems are mounted on the valve stem or are strapped on the rim, although they could also be mounted against the tire wall, for example. An electronic module generally includes a small battery, a circuit board with communication antennas or coils (receive and transmit), an air pressure sensor, a temperature sensor, a rotation detection device or accelerometer, a programmable controller and a memory for storing the sensor specific ID and other information depending on the TPMS system and capabilities. Modules that do not include a battery are under development. Due to the installation inside the tire or valve stem, sensors are designed to be permanently installed within the tire. Due to the finite life of batteries, power consumption is purposely low and the sensors are initially placed in a “sleep” mode so as to not use power until the vehicle or individual wheel is installed or sold to an end user. During operation of the vehicle in the field, it is common for the sensors to not be active or continuously reporting information to the vehicle ECU or continuously transmitting for receipt by an external TPMS tool, but rather to perform tire condition checks at predetermined intervals to conserve battery life. Therefore, it is often necessary to awaken or active a TPMS wheel sensor to receive data from the sensor on the condition of the tire. When activated, the sensors emit a signal or signals which are received and interpreted by the ECU or a nearby external TPMS tool and processed according to preprogrammed instructions.
External TPMS tools and devices have been deployed in high volume to communicate with vehicle TPMS wheel sensors and ECUs in new vehicle manufacturing plants. In one example, a TPMS tool unit is placed on each side of an assembly line, typically near the end where completed or near completed vehicles pass, to awaken the TPMS wheel sensors and communicate with the ECU to ensure that the TPMS system was installed and is operating as designed when the vehicle leaves the plant and is transported for sale in the field. An example of one system is the ATEQ model VT520 manufactured by ATEQ Corp. which is the assignee of the present invention which is incorporated herein by reference. These prior systems have several limitations including, but not limited to, limited capability to recognize or read a small number of different tire sensors, are typically limited to variables/information relating only to the tire or sensor itself (air pressure, temperature, sensor battery life etc.) and they do not track or store historical data on a particular tire sensor, tire or vehicle. These systems further are designed primarily for indoor, controlled environments, for example in enclosed assembly facilities.
In many industries or fields, for example managing a fleet of hundreds of rental cars or taxis in a major city, it is important for an efficient fleet to maintain proper tire pressure to keep the vehicles in service as much as possible. It would be very disadvantageous for customers of, for example, rental cars to require road service or return the vehicle because of low tire pressure during the rental period. Equally, customers of rental cars may not respond to a low tire pressure condition as they normally would with their own vehicles, and drive on low air pressure which may result in an unsafe driving condition or may damage the tire and other vehicle systems costing the rental car company money to repair the rental car and place the rental car back into the fleet for use.
In such rental car and taxi industries, it is common for companies to manually check the tire air pressure of each tire every time a vehicle is returned from use to ensure that it is ready to be returned to the fleet for use. In high volume car rental businesses at major airports or taxi companies in major cities, hundreds of vehicles a day may be rented and returned or undergo shift changes by the taxi drivers. At rental car facilities, often one or more individuals will be required full time to manually check the tire pressure and other vehicle conditions prior to a rental car leaving the facility and/or when it is returned so the vehicle can quickly be placed back into the fleet for use.
Further, it is known that, for example, rental cars are often subject to abuse and theft in a number of ways while out in the field. For example, new tires on a rental car may be stolen/removed by a thief or crime organization and replaced with a worn set of tires before the vehicle is returned to the rental company. The stolen new tires, along with the TPMS wheel sensors, are then sold for a profit. Removal and resale of the TPMS wheel sensors, which are not visible unless the tire is removed, go undetected by the rental company when the vehicle is initially returned, and it can cost the rental company hundreds of dollars to replace and reinstall a new sensor once the theft is detected.
Relatively high volumes of vehicles can also be experienced by quick lube/oil change/repair facilities where vehicles are only in a facility for 10-15 minutes and a facility may have multiple bays or lanes to service multiple vehicles at the same time. It is common for these facilities to provide quick inspection of important vehicle systems, for example tire air pressure, other vital fluids, vehicle mileage and other systems.
It would be advantageous to create systems and processes to monitor or inspect selected vehicle tire conditions in a high volume throughput environment to improve on the present, highly labor intensive process of checking tire air pressure and other conditions, as well as deterring theft or abuse of tires and related equipment.